5种产地九节菖蒲脂溶性成分GC-MS比较分析

分析鉴定和比较5种产地九节菖蒲中的脂溶性成分.采用索氏提取法提取脂溶性成分,甲酯化后采用气相色谱-质谱(GC-MS)联用技术分离并鉴定其组分,并用面积归一化法计算出各组分的相对百分含量.宁夏、山西、河南、四川和陕西九节菖蒲中分别鉴定出18、22、20、20种和20种脂溶性成分.5种产地九节菖蒲中的共有成分为8个,共有主成分为棕榈酸和亚油酸.不同产地九节菖蒲中脂溶性成分组成及相对含量差异较大,可为九节菖蒲的鉴别和临床应用提供参考.     

新疆紫花苜蓿籽脂肪酸化学成分的分析

采用索氏提取法提取新疆紫花苜蓿籽中的脂肪酸成分,进行甲酯化处理后用气相色谱-质谱联用技术分离和鉴定脂肪酸成分的组成和含量。结果表明,从紫花苜蓿籽中共分离鉴定出11种脂肪酸成分,占总量的86.71%,主要包括9,12,15-十八碳三烯酸（37.06%）、亚油酸（25.25%）、8-十四烯酸（8.1%）、棕榈酸（10.33%）等脂肪酸,其中不饱和脂肪酸占62.31%。     

三种鸢尾属植物的脂溶性成分比较分析

用GC-MS对矮紫苞鸢尾、细叶鸢尾和蓝花喜盐鸢尾这3种鸢尾植物的脂溶性成分进行了比较分析。从矮紫苞鸢尾中鉴定出11种脂溶性成分,占总峰面积的85.55%,相对含量较高的化合物为14-甲基十五烷酸甲酯(36.55%),(Z,Z)-9,12-十八烷二烯酸甲酯(10.05%);细叶鸢尾的脂溶性成分共鉴定出13种成分,占总峰面积的71.32%,相对含量较高的化合物为2-甲基-琥珀酸二丁酯(13.83%)、(Z,Z)-8,11-十八烷二烯酸甲酯(11.90%);蓝花喜盐鸢尾的脂溶性成分共鉴定出15种成分,主要以甲酸酯类为主,占总峰面积的90.54%,相对含量较高的化合物为十四烷酸甲酯(30.70%)、14-甲基-十五烷酸甲酯(26.83%)、十八烷酸甲酯(23.57%)。结果表明,从矮紫苞鸢尾中鉴定出的11种化合物为首次从该植物中发现。3种鸢尾属植物的脂溶性成分主要以有机酸酯类化合物为主,在其种类和相对含量上有一定的相似性,为该属植物化学分类提供一定的依据。     

GC-MS分析麦冬中脂溶性成分

用索氏提取法提取中药麦冬块根的脂溶性成分,经甲酯衍生化处理后采用气相色谱-质谱-计算机联用技术,分离鉴定其组成;运用峰面积归一化法定量分析。共鉴定出41种成分,占总成分的81.72%。其中脂肪酸成分的量占46.133%。含量较高的化合物为亚油酸(24.648%),棕榈酸(10.829%),6-十八碳烯酸(6.367%),愈创醇(6.757%)等。     

藏药迷果芹脂溶性成分分析

采用气相色谱-质谱（GC-MS）联用技术对藏药迷果芹的脂溶性成分进行分析.从藏药迷果芹石油醚萃取物中分离鉴定出26种化合物,占其总量的98.77％.在已鉴定的化学成分中,含量较高的化学成分依次为亚油酸（35.90％）、芹菜脑（23.98％）、棕榈酸（11.41％）、亚油酸乙酯（4.08％）、亚油酸甲酯（4.06％）、β-谷甾醇（4.40％）.本研究为开发迷果芹资源提供了科学依据.     

栽培宽叶缬草中的精油成分分析

采用水蒸气蒸馏法提取宽叶缬草精油,气相色谱-质谱分析其组成。从栽培宽叶缬草的精油成分中鉴定出6个化合物,共占精油总量的94.92%。它们分别是乙酸龙胆酯（60.19%）、（-）乙-酸桃金娘烯醇酯（3.87%）、α-乙酸松油酯（1.55%）、乙酰基蒈烯（1.68%）、α-芹子烯（26.07%）和（Z,E）α--法呢烯（1.56%）。结果表明乙酸龙胆酯和α-芹子烯是栽培缬草的主要成分。     

蛇百子中挥发油成分的GC-MS分析

对蛇百子全草中挥发油部分进行分析,研究其化学成分。采用水蒸气蒸馏法提取获得总挥发油（Ⅰ）,乙醚萃取得到挥发油（Ⅱ）,再用乙酸乙酯进一步提取得到挥发油（Ⅲ）,通过GC-MS技术对其进行分析。共分离鉴定出化学成分48种,其中挥发油（Ⅰ）鉴定出36种化合物、挥发油（Ⅱ）鉴定出30种化合物、挥发油（Ⅲ）鉴定出10种化合物。挥发油的主要成分为反式石竹烯、1,8-桉树脑、侧柏烯、α-香柑油烯、β-榄香烯、桉树脑、γ-古芸烯等。     

GC-MS分析川赤芍挥发油成分

采用水蒸气蒸馏法从川赤芍中提取挥发油,用气相色谱/质谱联用法（GC/MS）检测并分析其化学成分,用归一化法测定其相对含量,结果鉴定出37个成分,占挥发油总成分的86.15％.主要成分为苯甲酸、牡丹酚和邻甲基苯酚.     

普洱茶挥发性成分的GC-MS分析

采用同时蒸馏萃取法(SDE)提取普洱茶的挥发性成分,经气质联用分析鉴定,应用色谱峰面积归一化测定各成分的相对含量。经过对该茶样的分析,共鉴定出44种挥发性成分,占挥发性成分总量的92.46%,其中含量较高的化合物有醇类、酯类、酸类和苯衍生物,它们分别占总量的15.47%、12.43%、8.74%、32.36%。     

木香挥发油化学成分分析

使用水蒸气蒸馏法提取木香中的挥发油,利用气相色谱-质谱联用技术对木香化学成分进行分离鉴定,采用色谱峰面积归一化法确定各成分的相对含量。分析结果表明,共分离出53种组分,鉴定了其中的32个组分,占挥发油组分总量的60.38%。主要成分是（9Z,12Z,15Z）-9,12,15-十八烷基三亚乙基四胺-1-醇,反式石竹烯、α-紫罗酮、香叶基丙酮、石竹素、B-瑟林烯、A-姜黄烯。     

Structure and Properties of a cis-1,4-Polybutadiene/Organic Montmorillonite Nanocomposite Prepared via In Situ Polymerization

Cis-1,4-polybutadiene (cis-1,4-PB) is one of the most important synthetic rubbers, having superior performances such as wear resistance, cold resistance and high elasticity. However, its mechanical properties, including low tensile strength, tear resistance and thermal stability, limit its application in comparison to natural rubber and butadiene-styrene rubber that have excellent overall performances. Thus, the reinforcing of cis-1,4-PB is a necessity. The dispersion of clay in rubbers on the nanoscale can improve the mechanical, gas permeability and thermal properties of the resulting composites. In this paper, organic montmorillonite (OMMT) clay was dispersed into the cis-1,4-PB matrix via an in-situ polymerization method and the chemical structure, phase morphology, mechanical properties and thermal stability of the composite were investigated. The properties of the composite were analyzed by such techniques as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). In the in-situ polymerization, a Ni-based catalyst system with the presence of OMMT showed high efficiency and 1,4-selectivity for the polymerization of butadiene. The OMMT could be dispersed in the polymeric matrix on the nanoscale during the polymerization. The interfusion of OMMT had little influence on the thermal stability and the chemical micro-structure of the cis-1,4-PB when the content of cis-1,4 units was more than 95%. The loss tangent of the composite was higher than that of cis-1,4-PB from ?110 to ?55°C, the temperature range examined, and the mechanical properties of the cis-1,4-PB/OMMT nanocomposite (NC) were improved upon the addition of OMMT.     

东北苍耳子挥发油化学成分分析

利用乙醚抽提东北苍耳子挥发油,GC-MS结合计算机检索对其化学成分进行分析鉴定,用色谱峰面积归一化法计算各组分的相对含量.分离出89个组分,鉴定了其中74个组分,占总挥发油量的85.63%.东北苍耳子挥发油的主要成分为3-甲基丁酸(16.421%)、3-甲基-戊酸(15.882%)、苯乙醛(11.281%)、已酸(5.051%)、糠醛(4.716%)、苯甲醇(2.358%)、苯乙醇(2.282%)等.     

A Comparative Study on Hemp (Cannabis sativa)Essential Oil Extraction Using Traditional and Advanced Techniques

A comparative study of Cannabis sativa(Hemp)essential constituents obtained by using Supercritical Fluid Extraction(SCFE),Steam Distillation(SD)and Hydrodistillation(HD)is presented here.The optimized extraction temperatures were 130,110and 50℃for hydrodistillation,steam distillation and supercritical fluid extraction respectively.The essential oil of C.sativa was analyzed by using Gas chromatography mass spectrometry(GC-MS).A total of 33,30and 31components have been identified in HD,SD and SCFE respectively.Yield of essential oil using SCFE(0.039%)was more than HD(0.025%)and SD(0.035%)extraction respectively.The main component of sesquiterpenes obtained by hydrodistillation at 130℃with their percentages included caryophyllene(40.58%),trans-α-bergamotene(5.41%),humulene(10.97%),cis-β-farnesene(8.53%)and monoterpenes includedα-pinene(2.13%),d-limonene(6.46%),p-cymol(0.65%)and cineole(2.58%)respectively.The main component of sesquiterpenes obtained by SD steam distillation at110℃including caryophyllene(38.60%)trans-α-bergamotene(4.22%),humulene(10.26%),cis-β-farnesene(6.67%)and monoterpenes includedα-pinene(3.21%),d-limonene(7.07%),p-cymol(2.59%)and cineole(3.88%)whereas the more percentages of major components were obtained by SCFE at 50℃included caryophyllene(44.31%),trans-α-bergamotene(6.79%),humulene(11.97%)cis-β-farnesene(9.71%)and monoterpenes includedα-pinene(0.45%),d-limonene(2.13%)p-cymol(0.19%)and cineole(1.38%)respectively.We found yield/efficiency,chemical composition,quality of the essential oils by supercritical fluid extraction superior in terms of modern,green,saving energy and a rapid approach as compared to traditional techniques.     

Role of hydrogen migration in the mechanism of acetic acid elimination from MH(+) ions of acetates on chemical ionization and collision-induced dissociation

The elimination of acetic acid from the MH(+) ions of acetates of stereoisomeric 2-methyl-1-cyclohexanols and 1-hydroxy-trans-decalins exhibits a significant degree of stereospecificity under isobutane chemical ionization and collision-induced dissociation (CID) conditions, resulting in more abundant [MH - AcOH](+) ions in the cis-isomers 4c and 5tc than in their trans-counterparts 4t and 5tt. These findings suggest the involvement of a 1,2-hydride shift from the beta- to the alpha-position in the course of the acetic acid elimination from the MH(+) ions of the above cis-acetates, resulting in tertiary carbocation structures. The proposed mechanism of the elimination is supported by a considerable deuterium isotope effect detected in beta-deuterium-labeled cis-2-methyl-1-acetoxycyclohexane and by a CID study of the structures of the [MH - AcOH](+) ions obtained from cis- and trans-1,2-diacetoxycyclohexanes. Copyright 1999 John Wiley & Sons, Ltd.     

基于HPLC-DAD-SPE-CryoNMR-MS技术的代谢物快速定性和结构确定

快速定性并有效地确定代谢物结构是代谢组学、植物化学和天然药物发现等研究的重要内容. 本文以迷迭香的两种溶剂提取物（氯仿/甲醇=3/1和50%含水甲醇）作为模型样品,通过分析其中的一些化学成分,展现了HPLC-DAD-SPE-CryoNMR-MS无缝联仪技术在确定代谢物结构方面的应用潜力. 基于高效液相色谱、紫外吸收、核磁共振波谱及质谱数据,具有代表性的6个迷迭香代谢物的结构得到了确定,它们分别为1个酚类二萜（鼠尾草酚）、2个酚酸（迷迭香酸和咖啡酸）、2个黄酮（6-甲氧基木樨草素-7-葡萄糖苷和高车前甙）和1个香豆酸 (顺-4-香豆酸葡萄糖苷). 该技术使分析型HPLC柱所分离的组分可以获得高质量同核及异核二维核磁共振波谱,从而能够更加便捷地确定微量成分的结构. 这些研究结果不仅提供了上述6种代谢物详细的谱学数据,而且证实HPLC-DAD-SPE-CryoNMR-MS技术是天然产物以及其他复杂体系结构分析的重要工具,即使同一色谱峰中含有浓度相差一个数量级的多个代谢物时,该方法依然有效.     

Conformational structure of divinylacetylene

Ab initio quantum chemical calculations of the divinylacetylene molecule with different mutual orientations of vinyl groups are carried out using the 6–31G*/MP2 basis set. The torsional potential is approximated by a Fourier series. It is shown that the second term of the series dominates. The enthalpies of the cis- and trans-isomers are nearly equal; the maximum corresponds to the gosh-orientation (180.4 cm−1 with respect to the cis-form). The vibrational spectra of the compounds with cis-, gosh-, and trans-orientations of vinyl groups are analyzed based on the ab initio calculations. It is concluded that the experimental data available in the literature agree with the hypothesis that divinylacetylene exists as cis- and trans-isomers. Translated fromZhurnal Struktumoi Khimii, Vol. 39, No. 4, pp. 610–617, July–August, 1998.     

蕤核挥发油化学成分的分析

采用普通水蒸气蒸馏法提取蕤核挥发油,通过气相色谱-质谱(GC-MS)联用技术进行分析鉴定,共鉴定出33种化学组分,占挥发油总量的78.038%.主要含有斯巴醇(10.265%),亚油酸(8.075%),β-石竹烯(7.278%),7-辛烯-4-醇(6.572%),枯茗醛(4.435%),α-非兰烯醇(4.093%)等。